It's
very difficult to describe a degu. Often it is tried to compare
the degu with other pets, like the chinchilla, rat, gerbil or
even the squirrel. They look a bit like all of these rodents.

The colour of their fur is always brown/gray. The tips of the
hairs are black. The belly has a lighter colour. The thickness
of the fur depends on the environmental temperature. When it's
cold the fur will be thicker compared to when its warm. Sometimes
degus have one or more white spots in their fur, which is a sign
of domestication.

Wild degus can have a length of 40 cm
or longer (including their tail). If kept as pets they are much
smaller, about 25 - 30 cm. The size of a degu is comparable with
the size of a rat, however most times they will be even smaller.
Living in captivity rodents usually grow bigger than in the wild,
due to the better life circumstances. Degus form an exception
to this rule, which probably has to do with in-breeding.

Also the degu's tail can be compared with a rat's tail, but there
are a few differences. A rat's tail is naked, while a degu's
tail is hairy and has a little floss at it's tip. The
degu's tail is a bit shorter. Another important difference is
how they use their tail. A rat's tail hangs down and always drags
over the floor. The degu normally holds up it's tail and uses
it to keep balance.

The degu's eyes are dark brown. Very striking are their teeth,
which are coloured orange. The ears are much like chinchilla's
ears, they are relatively big and formed like a shelf. The four
legs each have five toes with pretty sharp nails. Degus use their
front legs to pick up objects, and to hold food, like a squirrel
does.

It's
difficult to see if a degu is male or female. There's only one
way to see what sex a degu has. You have to look at the distance
between the degu's anus and it's sexual organ. Female degus have
a small distance between these two, and males have a relatively
big distance. The sexual organ is a little protuberance with
both males and females, although it's a bit bigger with fertile
males.